Cellular
This article covers the practical aspects of wireless access to the Internet via Cellular. Introduction to Cellular Internet GSM :Global System for Mobile Communications (GSM) is a digital cellular communications technology based on Time Division Multiple Access (TDMA), and is the dominant mobile communications system in most of the world, including Europe, the Middle East, Africa, and Asia, and it now has a strong presence in North America as well. First introduced in 1991, the GSM standard has been deployed in four different frequency bands: 800 (called "850" so as not to be confused with D-AMPS on 800), 900, 1800, and 1900 MHz. GSM 850 and 1900 are primarily used in North America; GSM 900 and 1800 are primarily used outside of North America. GSM uses narrowband TDMA that allows up to eight (or sixteen with Half-Rate Codec1) simultaneous calls on the same radio frequency using different time slots in the same channel. Along with CDMA and D-AMPS (Digital AMPS, often referred to simply as "TDMA"), GSM represents the 2nd generation (2G) of cellular wireless. ::1. Initial public perception of Half-Rate Codec quality was so poor that it's not been generally used. However, adaptive encoding has improved quality substantially since then, so it's possible that Half-Rate Codec may be used more widely in the future, particularly in highly cost-sensitive markets (e.g., less developed countries). CSD :CSD (Circuit Switched Data) is similar to dialup modem communications. However, a GSM phone has no real modem, just a sort of virtual modem which makes a connection to a carrier's IWU (Inter-Working Unit), located in a service center. The IWU has the actual modem that makes analog data calls and/or fax calls over the PSTN (public switched telephone network). If the carrier doesn't provide the IWU facility, or if the account isn't provisioned for CSD, then a GSM phone cannot make data and/or fax calls. :Speed of CSD is 9.6 Kbps. :A regular dialup modem cannot be made to work over a GSM voice channel because of the audio data compression used. HSCSD GPRS :With a Class 10 device and good signal, typical download speeds of about 50 Kbps (about 6K Bytes/sec). Available in most GSM service areas. EGPRS(EDGE) :With a Class 10 device and good signal, typical download speeds of about 150 Kbps (about 18.5K Bytes/sec). Latency (as measured by ping) of about 300 ms. Widely available. Backward compatible to GPRS. UMTS :Typical download speeds of 200-320 Kbps (or about 2x EGPRS). Most (but not all; e.g., Novatel U520) devices are backward compatible to EGPRS and GPRS. HSDPA :Typical speeds are expected to be 400-700 Kbps (or about 4x EGPRS). Latency (as measured by ping) expected to be about 150 ms (or about 1/2 EGPRS). Backward compatible to UMTS, EGPRS and GPRS. CDMA 1xRTT EV-DO EV-DO Rev. A Carriers Cingular * Uses GSM/UMTS (AMPS/D-AMPS"TDMA" being migrated to GSM and phased out) * BroadbandConnect/EDGE(EGPRS) ** Laptops (notebooks) with integrated BroadbandConnect *** Dell Latitude *** Lenovo (IBM) ThinkPad **** Lenovo (IBM) website *** Sony VAIO ** Coverage Maps: ***BroadbandConnect ***EDGE(EGPRS) * Discussion Groups (lots of good info and help) ** alt.internet.wireless (general discussion) ** alt.cellular.cingular (Cingular) *** Google access to alt.cellular.cingular ** alt.cellular.attws (AT&T Wireless Service, now part of Cingular, newsgroup mostly dormant) *** Google access to alt.cellular.attws ** alt.cellular.data (cellular data communications) *** Google access to alt.cellular.data Sprint/Nextel * Uses CDMA (Sprint) and iDEN (Nextel) (iDEN expected to be migrated to CDMA and phased out) * Discussion Groups (lots of good info and help) ** alt.internet.wireless (general discussion) ** alt.cellular.sprintpcs (Sprint PCS) *** Google access to alt.cellular.sprintpcs ** alt.cellular.nextel (Nextel, now part of Sprint PCS) *** Google access to alt.cellular.nextel ** alt.cellular.data (cellular data communications) *** Google access to alt.cellular.data T-Mobile * Uses GSM * Discussion Groups (lots of good info and help) ** alt.internet.wireless (general discussion) ** alt.cellular.gsm.carriers.voicestream (original T-Mobile group) *** Google access to alt.cellular.gsm.carriers.voicestream ** alt.cellular.t-mobile (new T-Mobile group) *** Google access to alt.cellular.t-mobile (may not yet be available) ** alt.cellular.data (cellular data communications) *** Google access to alt.cellular.data Verizon * Uses CDMA * Discussion Groups (lots of good info and help) ** alt.internet.wireless (general discussion) ** alt.cellular.verizon (Verizon Wireless) *** Google access to alt.cellular.verizon ** alt.cellular.data (cellular data communications) *** Google access to alt.cellular.data WAP Wireless Application Protocol (WAP) is a protocol for wireless Internet access that is designed for small screen cellular phones. Access to the Internet is through a WAP Gateway. * WAP information WAP Gateways * BitNet (free) * TagTag (also free hosting) * wapmob.com (free) * Wappy (shaky) Wireless Broadband Routers * EVDO info * Junxion Box (works with CDMA or GSM) * Kyocera KR1 Mobile Router * Nexus Hawk (works with 802.11a/b/g, GSM and CDMA simultainiously) * Top Global routers